Nozzles are commonly used for directing and controlling the flow rate of fluids being dispensed. Some nozzles are specifically designed for dispensing liquid fuels such as gasoline and diesel, for example the nozzles disclosed in U.S. Pat. Nos. 6,024,140 and 5,603,364, which are hereby incorporated by reference for their teachings. Fuel dispensing nozzles generally include a control lever with an associated valve, and a spout. The lever controls the flow of the fuel passing through the spout, and is often located below a handle so that a user is able to grasp the handle with the palm of the hand, and extend the fingers to control the lever, and thus, the flow rate. Typically such devices include an auto-shutoff feature whereby a diaphragm or similar mechanism is responsive to the level of fuel in the container being filled, and dispensing is disrupted when the fuel is at a level that occludes a vacuum orifice in or near the tip of the nozzle spout. A limitation of existing fuel nozzles is that a volume of fuel remains in the interior of the spout and the vacuum orifice once the handle is released. This residual or post-dispense fuel, as represented by the shaded portions in the nozzles and spouts illustrated in FIGS. 1-4, for example, often drops on the ground, the user, the user's vehicle, and/or evaporates into free air, leading to the potential of a significant environmental problem. As the figures illustrate there are several potential locations in which residual liquids such as fuel may reside after dispensing has stopped. In the case of fuel dispensing nozzles, gasoline and similar fuels contain volatile organic compounds (VOCs) as well as hazardous air pollutants (HAPs), both of which have been targeted for reduction and/or elimination by the U.S. Environmental Protection Agency (EPA). Accordingly, there is a need for a fluid dispensing nozzle that reduces the wasteful dripping of residual fuel.
Although various nozzle designs have been proposed for use in fuel dispensing systems, environmental and safety concerns continue to demand that nozzles found in gas stations be designed to prevent fuel from dripping from the spout of the nozzle after it is removed from the fluid receptacle (e.g., vehicle fuel tank). Current designs, while somewhat effective, still present disadvantages, hence they have not been generally accepted. For example, some nozzles require complex valves at the end of the spout.
There are a number of different attributes which contribute to dripping from a nozzle. Two often overlooked sources of dripping originate from the vacuum line and the diaphragm. Fuel enters into the vacuum channels due to suction from the venturi. This results in a source of residual fuel and potential dripping from the venturi/vacuum channel. Once pumping has finished fuel is often ejected from the vacuum channel and runs along the bottom of the spout resulting in delayed drips. This gives the appearance that dripping has originated from the end of the spout. Dripping from the diaphragm occurs when fuel enters the diaphragm and adjacent air channels through the venturi. As the diaphragm displaces, mimicking a ‘syringe,’ causing the diaphragm to draw fuel through the venturi into the diaphragm and any adjacent vacuum channels. This residual fuel then results in delayed drips after the user has finished pumping.
Disclosed in embodiments herein is a liquid-dispensing apparatus having a spout, comprising: a main channel for directing the flow of a supply of liquid from an inlet end of the spout to a discharge end of the spout; a vacuum channel operatively associated with the dispensing apparatus, said vacuum channel having an open end in proximity with the discharge end of the spout and connecting to, and providing a source of intended fluid (e.g., vapor) to, at least one venturi located in proximity to the inlet end of the spout, where the vacuum channel further includes a fluid-sensitive valve proximate to the open end of the vacuum channel, and where said fluid-sensitive valve includes a movable stopper that may occupy a static position (when no flow of gas or liquid through the valve), an operating position (allowing air flow through the valve), and a closed position (where liquid is prevented from flowing through the valve); and at least one check-valve associated with the at least one venturi, wherein the check-valve prevents the backflow of fluid through the venturi.
Further disclosed in embodiments herein is a liquid-dispensing apparatus having a spout, comprising: a main channel for directing the flow of a supply of liquid from an inlet end of the spout to a discharge end of the spout; a vacuum channel operatively associated with the dispensing apparatus, said vacuum channel having an open end in proximity with the discharge end of the spout and connecting to, and providing a source of intended fluid to, at least one venturi located in proximity to the inlet end of the spout, wherein the vacuum channel further includes a fluid sensitive valve proximate to the open end of the vacuum channel system, where said valve includes a movable stopper that may occupy a static position (when there is no flow of fluid (liquid or gas) through the valve), an operating position (where fluid flow through the valve is under desired conditions), and a closed position (where flow conditions are no longer desirable, such that closing the valve is initiated and completed by undesirable flow (e.g., a change in viscosity, density, momentum, liquid-solid adhesion properties, etc.); and at least one check-valve associated with the at least one venturi, wherein the check-valve prevents the backflow of fluid and air through the venturi.
Also disclosed herein is a method for reducing the presence of liquid in a liquid-dispensing apparatus having a spout, and the spout having a main channel for directing the flow of a supply of liquid from an inlet end of the spout to a discharge end of the spout, the method comprising: providing a vacuum channel operatively associated with the liquid-dispensing apparatus, said vacuum channel having an open end in proximity with the discharge end of the spout and connecting to, and providing a source of intended fluid to a venturi(s) located in proximity to the inlet end of the spout; attaching a fluid-sensitive valve to the vacuum channel, proximate the open end of the vacuum channel, where said fluid-sensitive valve includes a movable stopper that may occupy a static position (when no flow of gas or liquid through the valve), an operating position (allowing air flow through the valve), and a closed position (where liquid is prevented from flowing through the valve); and inserting a check-valve in each venturi, wherein the check-valve prevents the backflow of fluid and air through the venturi.
The various embodiments described herein are not intended to limit the disclosure to those embodiments described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the various embodiments and equivalents set forth. For a general understanding, reference is made to the drawings. In the drawings, like references have been used throughout to designate identical or similar elements. It is also noted that the drawings may not have been drawn to scale and that certain regions may have been purposely drawn disproportionately so that the features and aspects could be properly depicted.